I have had all three brands (Shoei, Arai and Suomy) they do not cross over very well as the Shoei and Arai are more for "oval" heads and the Suomy is for a more rounded skull.... (the Suomy fits too tight around the forehead and back for my head type)
In my case, I fit the Arai/Shoei and the Suomy has to be sized larger as it does not really fit my head correctly..
It is unlikely that all three brands are good for any one person IMO... if you have not tried them on, I would find a couple to see how they fit before spending a dime...